Pokhara University
Level: Bachelor | Semester: Fall | Year: 2015
Programme: B.Sc. Environmental Management
Course: Introductory Chemistry

Full Marks: 100 | pass Marks: 45 | Time: 3 Hrs
Candidates are required to give their answers in their own words as far as practicable. The figures in the margin indicates full marks.

Attempt all the questions.

1. a) Define Boyle’s law and Charle’s law? Write the combine gas equation. Gas A diffuses four times faster than gas B of molecular weight 64. Calculate the density of A. [7]
   b) Define acid and base on the basis of three different concepts. What are the limitations of Bronsted Lowry Concept. Show your acquaintance with conjugate acid – base pairs. [8]
   OR
   a) Explain how can you manufacture ammonia by Haber’s process? [8]
   b) Define Chromatography. Explain how a gases are analyzed by a chromatograph. Write down a sketch diagram of a gas chromatograph. [7]
2. a) What are the basic postulates of kinetic theory of gases? [5]
   b) What is ionization energy of an element? What trend do you find in the periodic table when you go from left to right and why? [5]
   c) What are the features of modern periodic table? [5]
3. a) Explain how organic compounds can be classified? [5]
   b) Define functional group and what are the functional group of ester, aldehyde amide and ether. Give on example for each. [5]
   c) Show how Nylon 6, 6 and terylene be obtained from its monomer units. [5]
4. a) Derive the relation between K_p and K_c. What is the condition for a gaseous reaction to have K_p=K_c. [8]
   b) State Hess’s law of constant heat of summation. Illustrate Hess’s law by giving suitable example. [7]
5. a) State Mendeleev’s periodic law and Modern periodic law. What are the drawbacks of Mendeleev’s periodic law. [5]
   b) Define order of reaction. Derive the rate constant for first order reaction. [5]
   c) Show your acquaintance with lyophillic sols and lyophobic sols. [5]
6. a) What is solubility product? What are the principles of solubility product regarding saturated and unsaturated solution? [7]
   b) What are the colloidal solutions? Explain the various ways of Flocculating the colloidal solutions? [8]
7. Write short notes on any two: [5 X 2]
   a) Common ion effect
   b) Differences between photochemical reaction and thermal reactions
   c) Convert:
   i) benzene into notrobenzene
   ii) Methylamine into ethyl amine